:root{--fstack:-apple-system,"SF Pro Text",Inter,"Segoe UI",Roboto,"Noto Sans","Hiragino Sans","PingFang SC","Hiragino Kaku Gothic ProN","Apple SD Gothic Neo",sans-serif;}
:root,[data-theme="light"]{
  --indigo:#4F46E5;--indigo-soft:#EEF2FF;--indigo-line:#1E1B4B;
  --page:#F8FAFC;--card:#FFFFFF;--ink:#0B1120;--text:#0B1120;--muted:#475569;
  --border:#E2E8F0;--border2:#475569;--chip-bg:#EEF2FF;--ok-bg:#F0FDF4;--ok:#15803D;
  --keep-bg:#F8FAFC;--shadow:0 12px 32px rgba(11,17,32,.14);
}
[data-theme="dark"]{
  --indigo:#A5B4FC;--indigo-soft:#1E1B4B;--indigo-line:#A5B4FC;
  --page:#0B1120;--card:#1E293B;--ink:#F8FAFC;--text:#E2E8F0;--muted:#94A3B8;
  --border:#475569;--border2:#475569;--chip-bg:#1E293B;--ok-bg:#14291C;--ok:#4ADE80;
  --keep-bg:#0F172A;--shadow:0 12px 32px rgba(0,0,0,.5);
}
*{margin:0;padding:0;box-sizing:border-box;}
body{font-family:var(--fstack);background:var(--page);color:var(--text);min-height:100vh;display:flex;flex-direction:column;}
a{color:var(--indigo);}

.nav{background:var(--card);border-bottom:1px solid var(--border);padding:14px 64px;
     display:flex;align-items:center;gap:14px;position:relative;z-index:30;}
.logo-mark{width:40px;height:40px;border-radius:10px;background:#4F46E5;position:relative;flex:none;}
.logo-mark .b1{position:absolute;left:6px;bottom:8px;width:14px;height:10px;border-radius:4px 4px 4px 0;background:#EA580C;}
.logo-mark .b2{position:absolute;right:6px;top:8px;width:9px;height:8px;border-radius:3px;background:#EA580C;}
.logo-name{font-size:21px;font-weight:800;color:var(--ink);letter-spacing:-.3px;text-decoration:none;}
.logo-name span{color:#EA580C;}
.nav .links{margin-left:auto;display:flex;gap:28px;font-size:15px;color:var(--text);font-weight:500;}
.nav .links a{color:inherit;text-decoration:none;}
.nav .links a:hover{color:var(--indigo);}
.nav .links .on{color:var(--indigo);font-weight:700;}
.theme-btn{width:36px;height:36px;border-radius:10px;border:1px solid var(--border2);
     background:var(--card);color:var(--text);font-size:16px;cursor:pointer;flex:none;}
.lang-dd{position:relative;}
.lang-btn{font-size:14px;font-weight:700;color:var(--indigo);background:var(--indigo-soft);
     border:1px solid var(--indigo-line);border-radius:10px;padding:8px 14px;cursor:pointer;}
.lang-menu{display:none;position:absolute;right:0;top:44px;background:var(--card);
     border:1px solid var(--border);border-radius:12px;padding:8px;min-width:200px;
     box-shadow:var(--shadow);z-index:50;}
.lang-menu.open{display:block;}
.lang-menu a{display:block;padding:8px 12px;border-radius:8px;font-size:14px;color:var(--text);text-decoration:none;}
.lang-menu a:hover{background:var(--indigo-soft);color:var(--indigo);}
.lang-menu a.on{color:var(--indigo);font-weight:700;background:var(--indigo-soft);}
.lang-menu a.off{color:var(--muted);opacity:.55;cursor:not-allowed;}
.lang-menu .sep{border-top:1px solid var(--border);margin:6px 4px;}

.page-head{background:var(--card);border-bottom:1px solid var(--border);padding:48px 64px 44px;}
.wrap{max-width:920px;margin:0 auto;}
.crumb{font-size:13px;font-weight:700;letter-spacing:1.2px;text-transform:uppercase;color:var(--indigo);margin-bottom:12px;}
h1{font-size:36px;font-weight:800;color:var(--ink);letter-spacing:-.5px;line-height:1.2;}
.page-head p.sub{font-size:16.5px;color:var(--text);line-height:1.7;margin-top:12px;max-width:640px;}
.doc-meta{margin-top:18px;display:flex;flex-wrap:wrap;gap:10px;align-items:center;font-size:13px;color:var(--muted);}
.doc-meta .pill{background:var(--indigo-soft);color:var(--indigo);font-weight:700;border-radius:999px;padding:5px 13px;}

main{padding:36px 64px 56px;flex:1;}
.card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:28px 30px;margin-top:22px;}
.card>h2{font-size:20px;font-weight:800;color:var(--ink);display:flex;align-items:center;gap:10px;}
.stepnum{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;flex:none;
     border-radius:9px;background:var(--indigo);color:#FFF;font-size:15px;font-weight:800;}
.card p{font-size:15px;line-height:1.75;margin-top:12px;color:var(--text);}
.card ul,.card ol{margin:12px 0 0 22px;font-size:15px;line-height:1.8;color:var(--text);}
.muted{color:var(--muted);}

.email-card{border:2px solid var(--indigo);box-shadow:var(--shadow);}
.email-row{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin-top:16px;}
.email-text{font-size:19px;font-weight:800;color:var(--indigo);letter-spacing:-.2px;}
.btn{display:inline-block;background:var(--indigo);color:var(--page);font-size:15.5px;font-weight:700;
     padding:12px 26px;border-radius:12px;text-decoration:none;border:none;cursor:pointer;
     font-family:var(--fstack);}
.btn:hover{filter:brightness(1.08);}
.btn-ghost{background:transparent;color:var(--indigo);border:2px solid var(--indigo);padding:10px 24px;}
.copied{font-size:13.5px;font-weight:700;color:var(--ok);display:none;}
.copied.show{display:inline;}

.duo{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:16px;}
.duo .box{border:1px solid var(--border);border-radius:12px;padding:18px 20px;}
.duo .box.del{background:var(--ok-bg);}
.duo .box.keep{background:var(--keep-bg);}
.duo h3{font-size:15px;font-weight:800;color:var(--ink);}
.duo ul{margin:10px 0 0 20px;font-size:14.5px;line-height:1.8;}

details{border:1px solid var(--border);border-radius:12px;margin-top:12px;background:var(--card);}
summary{cursor:pointer;font-size:15px;font-weight:700;color:var(--ink);padding:15px 18px;list-style:none;}
summary::-webkit-details-marker{display:none;}
summary::before{content:"▸ ";color:var(--indigo);font-weight:800;}
details[open] summary::before{content:"▾ ";}
details .a{padding:0 18px 16px;font-size:14.5px;line-height:1.75;color:var(--text);}

.legal-line{margin-top:26px;font-size:13.5px;color:var(--muted);line-height:1.8;}
footer{border-top:1px solid var(--border);background:var(--card);padding:22px 64px;
     font-size:13px;color:var(--muted);display:flex;flex-wrap:wrap;gap:14px;align-items:center;}
footer .proto{margin-left:auto;font-size:12px;}
footer .proto a{color:var(--muted);}
@media (max-width:760px){
  .nav,.page-head,main,footer{padding-left:20px;padding-right:20px;}
  h1{font-size:28px;}
  .duo{grid-template-columns:1fr;}
  .nav .links{display:none;}
}